MoS2_CNTs_aerogel-based PEDOT nanocomposite electrochemical sensor for simultaneous detection of chloramphenicol and furazolidone in food samples.

Toxic intermediates in food caused by chloramphenicol (CP) and furazolidone (FZ) have gained interest in research toward their detection. Hence, fast, reliable, and accurate detection of CP and FZ in food products is of utmost importance. Here, a novel molybdenum disulfide-connected carbon nanotube aerogel/poly (3,4-ethylenedioxythiophene) [MoS2/CNTs aerogel/PEDOT] nanocomposite materials are constructed and deposited on the pretreated carbon paste electrode (PCPE) by a facile eletropolymerization method. The characterization of MoS2/CNTs aerogel/PEDOT nanocomposite was analyzed by scanning electron microscopy (SEM), cyclic voltammetry, and differential pulse voltammetry. The modified MoS2/CNTs aerogel/PEDOT nanocomposite has improved sensing characteristics for detecting CP and FZ in PBS solution. For this work, we have studied various parameters like electrocatalytic activity, the effect of scan rates, pH variation studies, and concentration variation studies. Under optimum conditions, the modified electrode exhibited superior sensing ability compared to the bare and pretreated CPE. This improvement in electrocatalytic activity can be the higher conductivity, larger surface area, increased heterogeneous rate constant, and presence of more active sites in the MoS2/CNTs aerogel/PEDOT nanocomposite. The modified electrode demonstrated distinct electrochemical sensing toward the individual and simultaneous analysis of CP and FZ with a high sensitivity of 0.701 µA. µM-1 .cm-2 for CP and 0.787 µA. µM-1 .cm-2 for FZ and a low detection limit of 3.74 nM for CP and 3.83 nM for FZ with good reproducibility, repeatability, and interferences. Additionally, the prepared sensor effectively detects CP and FZ in food samples (honey and milk) with an acceptable recovery range and a relative standard deviation below 4%.

Liposomal Drug Delivery against Helicobacter pylori Using Furazolidone and N-Acetyl Cysteine in Augmented Therapy.

Helicobacter pylori (H. pylori) infection is a significant global health concern, affecting approximately 50% of the world's population and leading to gastric ulcers, gastritis, and gastric cancer. The increase in antibiotic resistance has compromised the efficacy of existing therapeutic regimens, necessitating novel approaches for effective eradication. This study aimed to develop a targeted liposomal drug delivery system incorporating furazolidone and N-acetylcysteine (NAC) to enhance mucopenetration and improve Helicobacter pylori eradication. Liposomes were formulated with furazolidone, NAC, and Pluronic F-127 using a modified reverse-phase evaporation technique. The formulations were categorized based on charge as neutral, negative, and positive and tested for mucopenetration using a modified silicon tube method with coumarin-6 as a fluorescent marker. The encapsulation efficiency and particle size were analyzed using HPLC and an Izon q-nano particle size analyzer. The results indicated that charged liposomes showed a higher encapsulation efficiency than neutral liposomes with Pluronic F-127. Notably, combining furazolidone with 1% NAC achieved complete eradication of H. pylori in 2.5 h, compared to six hours without NAC. The findings of this study suggest that incorporating NAC and Pluronic F-127 into liposomal formulations significantly enhances mucopenetration and antimicrobial efficacy.

Colorimetric immunoassay of furazolidone metabolites based on iron-copper bimetallic organic framework nanoenzyme.

Based on the peroxidase activity of Cu-hemin metal-organic framework (Cu-hemin MOF) nanozyme, a colorimetric enzyme-linked immunosensor was developed for the detection of furazolidone (FZD). Cu-hemin MOF is a bimetallic nanozyme that exhibited a stronger catalytic effect compared with single-metal organic framework nanoenzymes. Cu-hemin-MOF catalyzes hydrogen peroxide (H2O2) to produce hydroxyl radicals (•OH), which oxidizes the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB). The absorbance change is at 650 nm. The content of AOZ in animal food can be quickly and accurately determined by changes in absorbance. The linear range of the colorimetric biosensor for detecting FZD was 0.01 ~ 62.52 ng/mL, and the limit of detection was as low as 0.01 ng/mL. The recovery of spikes samples was in the range 94.2-108.0 % and reproducibility was less than 4.8%. In addition, the cross-reaction rate was less than 0.1% when detecting other metabolites except AOZ, indicating that the sensor has good applicability and specificity. This study not only provides a better understanding of the relationship between the dispersion of nanoenzymes and enzyme-like activity but also offers a general method for detecting antibiotics using the nanoenzyme colorimetric method.

Exploring the economic viability of electrochemical assessment for water contaminants with NiFe-PBA/ZIF-67 core shell modified GCE.

Zeolitic Imidazolate (metal organic) Frameworks (ZIFs) and Prussian Blue Analogues (PBAs) are promising materials in electrochemical sensing due to their unique properties. In this study, a composite material comprising NiFe-PBA and ZIF-67 was synthesized and made to form a uniform layer onto a glassy carbon electrode (GCE) to enhance electrochemical performance for furazolidone (FZD) detection. The synthesized NiFe-PBA/ZIF-67 composite exhibited excellent sensitivity, selectivity, and stability towards FZD detection, with a low limit of detection (LOD). The electrochemical behaviour of FZD on the NiFe-PBA/ZIF-67/GCE electrode was investigated, revealing a diffusion-controlled process. Differential pulse voltammetry (DPV) analysis demonstrated the synergetic effect of the PBA/MOF core-shell structure in enhancing FZD electro-reduction. The sensor exhibited exceptional LOD of 0.007 µM. Selectivity studies confirmed the sensor's ability to distinguish FZD from potential interferents. Extensive evaluations demonstrated the sensor's reproducibility, repeatability, and long-term stability, affirming its practical utility. Real sample analysis further validated the sensor's excellent analytical capabilities in diverse matrices.

Anti-Helicobacter pylori Infection Treatment and Pulmonary Hypersensitivity: Case Series and Review of the Literature.

BACKGROUND: Helicobacter pylori (H. pylori) infection is currently widespread throughout the world. Bismuth-containing quadruple therapy is widely used, but it has rarely been associated with interstitial lung disease. CASE PRESENTATION: We described six cases with similar clinical symptoms and typical pulmonary interstitial imaging changes during anti-H. pylori therapy, usually on Days 7-12 following treatment. Anti-H. pylori infection treatment was discontinued when it was suspected to be the cause of the clinical symptoms, and all of the patients accepted observation therapy. All of them had a favorable outcome, the clinical symptoms returned to normal almost 1 week later, and the chest computed tomography (CT) scan images showed remarkable absorption 4 weeks later. CONCLUSIONS: Drug interactions could be the cause, and the most likely drug was furazolidone. All of the patients recovered quickly after drug discontinuation, and low-dose steroid may help shorten the recovery time.

Application of furazolidone in Helicobacter pylori infection eradication.

Increasing antibiotic resistance is the primary reason for treatment failure of Helicobacter pylori (H. pylori) infection. To enhance the eradication rate, minimize the development of secondary resistance, and alleviate the socioeconomic burden, it is crucial to select H. pylori-sensitive antibiotics carefully. Furazolidone has been used for H. pylori eradication in developing countries for decades due to its affordability and low resistance rate. Numerous studies have demonstrated that furazolidone-containing regimens are more efficacious than those containing other antibiotics, as both first- and second-line therapies, and are also well tolerated. However, utility of furazolidone is restricted or not optimal in certain countries due to its infrequent but potentially severe adverse effects. The decision to discontinue usage of furazolidone because of concerns regarding adverse effects may be misguided. Here we comprehensively reviewed the studies on furazolidone at different dosages and treatment durations for H. pylori eradication. Further research on the mechanisms of action and clinical trials of furazolidone are of great practical importance.

Rapid chemical reduction synthesis of copper nanoclusters with blue fluorescence for highly sensitive detection of furazolidone.

Tannic acid (TA), as a stabilizing agent, was successfully utilized to establish blue-emitting copper nanoclusters (TA-Cu NCs) on the basis of a facile chemical reduction preparation method. Characterization results proved successful synthesis of TA-Cu NCs with uniform size and excellent stability. TA-Cu NCs exhibited a blue emission wavelength at 431 nm when excited at 364 nm. Interestingly, the as-prepared TA-Cu NCs were selectively quenched by furazolidone based on static quenching. In addition, this analysis platform for furazolidone detection had an excellent linear range from 0.5 to 120 µM with a detection limit of 0.074 µM (S/N = 3). Furthermore, the accuracy of this sensing method was successfully confirmed by detecting furazolidone in bovine serum samples, indicating that TA-Cu NCs had bright application prospects.

Rapid determination of furazolidone residues in animal foods by time-resolved fluorescence immunochromatography.

Although furazolidone (FZD) was completely banned from livestock production in many countries many years ago due to its mutagenicity and carcinogenicity, the abuse of FZD is still common today. Accurate and rapid detection of FZD residues in animal-derived food products is highly important for human health. Here, a time-resolved fluorescence immunochromatography (TRFI) test strip for rapid and quantitative detection of 3-amino-2-oxazolidinone (AOZ) residues in animal foods was developed and validated. Its limit of detection and limit of quantification were 0.05 and 0.14 µg/kg, respectively. The typical recovery rates were 95-105 % in chicken breast samples spiked with the AOZ standard substance at concentrations of 0.05-2 µg/kg, with a coefficient of variation value ≤8.5 %. The cross-reaction rates of the TRFI-AOZ test strips with 3-amino-5-morpholinomethyl-2-oxazolidone, semicarbazide, and 1-amino-imidazolidin-2,4-dione were less than 1 %. The newly developed TRFI test strip has high sensitivity, high specificity, cost effectiveness and user-friendly control, and is suitable for the rapid and large-scale screening of AOZ residues in animal foods.

Exploring Alternative Treatment Choices for Multidrug-Resistant Clinical Strains of Helicobacter pylori in Mongolia.

Helicobacter pylori is a pathogen related to severe diseases such as gastric cancer; because of rising antimicrobial-resistant strains, failure to eradicate H. pylori with antibiotics has increased worldwide. Multidrug-resistant H. pylori and gastric cancer is common in Mongolia; therefore, we aimed to explore alternative antimicrobial treatments and the genomes of resistant strains in this country. A total of 361 H. pylori strains isolated from patients in Mongolia were considered. Minimal inhibitory concentrations for two fluoroquinolones (ciprofloxacin and moxifloxacin), rifabutin, and furazolidone were determined via two-fold agar dilution. Genomic mutations in antibiotic-resistant strains were identified by next-generation sequencing using the Illumina Miseq platform and compared with genes from a reference H. pylori strain (26695). The resistance rate of H. pylori strains to quinolones was high (44% to ciprofloxacin and 42% to moxifloxacin), and resistance to rifabutin was low (0.5%); none were resistant to furazolidone. Most quinolone-resistant strains possessed gyrA gene mutations causing amino acid changes (e.g., N87K, A88P, and D91G/Y/N). While one rifabutin-resistant strain had amino acid-substituting mutations in rpoB (D530N and R701C), the other had three novel rpoB mutations; both rifabutin-resistant strains were sensitive to furazolidone. Overall, our findings suggest that rifabutin and/or furazolidone may be an alternative, effective H. pylori treatment in patients who have failed to respond to other treatment regimens.

Thiol-Based Modification of MarR Protein VnrR Regulates Resistance Toward Nitrofuran in Vibrio cholerae By Promoting the Expression of a Novel Nitroreductase VnrA and of NO-Detoxifying Enzyme HmpA.

Aims: Epidemiological investigations have indicated low resistance toward nitrofuran in clinical isolates, suggesting its potential application in the treatment of multidrug-resistant bacteria. Therefore, it is valuable to explore the mechanism of bacterial resistance to nitrofuran. Results: Through phenotypic screening of ten multiple antibiotic resistance regulator (MarR) proteins in Vibrio cholerae, we discovered that the regulator VnrR (VCA1058) plays a crucial role in defending against nitrofuran, specifically furazolidone (FZ). Our findings demonstrate that VnrR responds to FZ metabolites, such as hydroxylamine, methylglyoxal, hydrogen peroxide (H2O2), ß-hydroxyethylhydrazine. Notably, VnrR exhibits reversible responses to the addition of H2O2 through three cysteine residues (Cys180, Cys223, Cys247), leading to the derepression of its upstream gene, vnrA (vca1057). Gene vnrA encodes a novel nitroreductase, which directly contributes to the degradation of FZ. Our study reveals that V. cholerae metabolizes FZ via the vnrR-vnrA system and achieves resistance to FZ with the assistance of the classical reactive oxygen/nitrogen species scavenging pathway. Innovation and Conclusion: This study represents a significant advancement in understanding the antibiotic resistance mechanisms of V. cholerae and other pathogens. Our findings demonstrate that the MarR family regulator, VnrR, responds to the FZ metabolite H2O2, facilitating the degradation and detoxification of this antibiotic in a thiol-dependent manner. These insights not only enrich our knowledge of antibiotic resistance but also provide new perspectives for the control and prevention of multidrug-resistant bacteria.

Efficacy and safety of a 14-day modified concomitant therapy for refractory Helicobacter pylori infection: a pilot study.

BACKGROUND AND AIM: After three treatment failures, Helicobacter pylori infection is deemed refractory as antibiotic treatment options become significantly limited. This study evaluated the efficacy and safety of a 14-day modified concomitant therapy for managing refractory H. pylori infection. METHODS: Patients who had failed to respond to three or more rounds of H. pylori therapies were recruited for this study. They received a 14-day modified concomitant therapy, including esomeprazole 40 mg, amoxicillin 1000 mg, and furazolidone 100 mg twice daily and tetracycline 500 mg four times daily. Demographic data, adverse events, and patient compliance were recorded. The presence of H. pylori was reevaluated 6 weeks following treatment. Eradication rate was assessed as the primary outcome. RESULTS: Overall, 59 participants received the 14-day modified concomitant therapy. In the intention-to-treat and per-protocol analyses, the eradication rate was 84.7% (50/59) and 89.3% (50/56), respectively. H. pylori was successfully isolated from 75.0% (12/16) of patients. The resistance rate of H. pylori to metronidazole, levofloxacin, and clarithromycin was 91.7% (11/12), 58.3% (7/12), and 50.0% (6/12), respectively. Resistance to amoxicillin, furazolidone, or tetracycline was not observed. The frequency of adverse events was 35.6% (21/59), with no serious adverse events reported. CONCLUSION: The 14-day modified concomitant therapy appears to be appropriate for refractory H. pylori infection and is particularly promising for the Chinese population. A randomized controlled trial is warranted to verify its efficacy, especially in the current environment of increasing antibiotic resistance.

Delayed-type allergic reaction to furazolidone: A case report and review of the literature.

BACKGROUND: Furazolidone is a nitrofuran antimicrobial agent used in the treatment of bacterial and protozoal infections. Hypersensitivity to furazolidone is rarely reported and only eight cases have been documented in English since 1967. OBJECTIVES: To report a 24-year-old man who developed exanthematous drug eruptions in general and swelling sensation of the hands after first dose of oral administration of medicines for Helicobacter pylori infection 7 h later, who was finally confirmed with delayed-type IV allergic reaction to furazolidone by provocation tests. And to review the existing literature. METHODS: Thorough clinical examination, prick, intradermal, and patch tests, drug provocation tests were performed in the patient. RESULTS: Skin tests of all used drugs were negative. Drug provocation tests to furazolidone resulted to be positive. CONCLUSIONS: Clinicians should be aware that furazolidone may induce delayed-type allergic reactions; diagnostic approaches should be taken to identify the responsible drug when multiple medications were used concurrently.

Nanomechanical changes in probiotic bacteria under antibiotics exposure: Implications on Lactobacillus biofilm formation.

Recognition of the microbial cell's surface constituents' biophysical properties is an important research topic, allowing a better understanding of the cell's behaviour under different conditions. Atomic force microscopy (AFM) was employed in this study to analyse the basis of the nanomechanical changes in probiotic bacteria under nitrofurantoin, furazolidone, and nitrofurazone exposure. Recorded significant changes in the two Lactobacillus strains cells morphology, topography, and adhesion parameters resulted in the increase of the cells' longitude (up to 2.58 µm), profile height (by around 0.50 µm), and decrease in the adhesion force (up to 13.58 nN). Young's modulus and adhesion energy decreased within 96 h, however with no negative effect on the cells' morphology or loss of structural integrity. Observed modifications present the mode of action of the 5-nitrofuran derivative antibiotics on probiotic biofilm formation and suggest activation of the multilevel adaptation mechanisms to counteract unfavorable environments. A visual change in bacterial morphology such as an increased surface-to-volume ratio might be a link between molecular-level events and outcomes in individual cells and biofilms. This paper for the first time shows, that these antibiotics affect the properties of non-target microorganisms as lactobacilli, and might impair biofilm formation. However, the degree of such transformations depends on the delivered active substance.

Efficacy and safety of modified tetracycline dosing in a quadruple therapy for Helicobacter pylori: A retrospective single center study.

BACKGROUND: Although highly effective as a component of Helicobacter pylori (H. pylori) treatment regimen, tetracycline is associated with a high incidence of medication-related adverse events. Modified dosing of tetracycline as part of quadruple therapy may improve safety while providing comparable eradication rates. AIM: To evaluate the efficacy and safety of modified dosing of tetracycline in patients receiving tetracycline and furazolidone-containing quadruple therapy in patients with H. pylori infection. METHODS: Consecutive patients (10/2020-12/2021) who received tetracycline and furazolidone quadruple therapy for H. pylori infection at Sir Run Run Shaw Hospital were identified. All patients received tetracycline, furazolidone, proton pump inhibitor, and bismuth for 14 d as primary or rescue therapy. Modified tetracycline dose group received tetracycline 500 mg twice daily while standard group received 750 mg twice daily or 500 mg three times daily. RESULTS: Three hundred and ninety-four patients [mean age = 46.3 ± 13.9, male = 137 (34.8%), and 309 (78.4%) primary therapy] completed tetracycline and furazolidone quadruple therapy for H. pylori infection including those who received modified tetracycline dose in 157 and standard doses in 118 (750 mg twice daily) and 119 (500 mg three times daily). Eradication rates in the modified tetracycline dose group were 92.40% and in the standard groups, eradication rates were 93.20% for 750 mg twice daily group and 92.43% for 500 mg three times daily group, respectively, without statistical difference (P = 0.959). The incidence of adverse events was lower in the modified tetracycline dose (15.3% vs 32.3% and 29.4%; P = 0.002) compared to the standard dose group. CONCLUSION: In a real-world experience, modified tetracycline dosing as part of tetracycline and furazolidone quadruple therapy for 14 d demonstrated high efficacy, comparable to standard tetracycline dose regimens, with a favorable safety profile.

Catalytically enhanced direct degradation of nitro-based antibacterial agents using dielectric barrier discharge cold atmospheric pressure plasma and rhenium nanoparticles.

The common utilization of antimicrobial agents in medicine and veterinary creates serious problems with multidrug resistance spreading among pathogens. Bearing this in mind, wastewaters have to be completely purified from antimicrobial agents. In this context, a dielectric barrier discharge cold atmospheric pressure plasma (DBD-CAPP) system was used in the present study as a multifunctional tool for the deactivation of nitro-based pharmacuticals such as furazolidone (FRz) and chloramphenicol (ChRP) in solutions. A direct approach was applied to this by treating solutions of the studied drugs by DBD-CAPP in the presence of the ReO4- ions. It was found that Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS), generated in the DBD-CAPP-treated liquid, played a dual role in the process. On the one hand, ROS and RNS led to the direct degradation of FRz and ChRP, and on the other hand, they enabled the production of Re nanoparticles (ReNPs). The produced in this manner ReNPs consisted of catalytically active Re+4, Re+6, and Re+7 species which allowed the reduction of -NO2 groups contained in the FRz and ChRP. Unlike the DBD-CAPP, the catalytically enhanced DBD-CAPP led to almost FRz and ChRP removals from studied solutions. The catalytic boost was particularly highlighted when catalyst/DBD-CAPP was operated in the synthetic waste matrix. Re-active sites in this scenario led to the facilitated deactivation of antibiotics, achieving significantly higher FRz and ChRP removals than DBD-CAPP on its own.

Furazolidone-induced pulmonary toxicity in Helicobacter pylori infection: Two case reports.

BACKGROUND: Helicobacter pylori (H. pylori) infection is a global problem, causing significant morbidity and mortality. Furazolidone is recommended to eradicate H. pylori infections in China owing to the highly associated antibiotic resistance. CASE SUMMARY: This article presents two cases of lung injury caused by furazolidone treatment of H. pylori infection and the relevant literature review. Two patients developed symptoms, including fever, cough, and fatigue after receiving a course of furazolidone for H. pylori infection. Chest computed tomography showed bilateral interstitial infiltrates. Laboratory studies revealed elevated blood eosinophil count. After discontinuing furazolidone with or without the use of corticosteroids, the symptoms improved rapidly. A PubMed database literature search revealed three reported cases of lung injury suggestive of furazolidone-induced pulmonary toxicity. CONCLUSION: Clinicians should be aware of the side effects associated with the administration of furazolidone to eradicate H. pylori infection.

[Effectiveness of empirical Helicobacter pylori eradication therapy with furazolidone in Russia: results from the European Registry on Helicobacter pylori Management (Hp-EuReg)].

BACKGROUND: First-line therapy does not always provide a high level of Helicobacter pylori eradication due to the increase of H. pylori resistance to antibiotics; therefore, it remains necessary to identify the most effective rescue treatments. The purpose of this study was to evaluate the efficacy and safety of empirical H. pylori furazolidone-containing regimens. MATERIALS AND METHODS: Adult H. pylori infected patients empirically treated with furazolidone-containing eradication regimens were registered in an international, prospective, multicenter non-intervention European registry on H. pylori management (Hp-EuReg). Data were collected at AEG-REDCap e-CRF from 2013 to 2021 and the quality was reviewed. Modified intention-to-treat (mITT) effectiveness analyses were performed. RESULTS: Overall 106 patients received empirical furazolidone-containing therapy in Russia. Furazolidone was prescribed in a sequential scheme along with amoxicillin, clarithromycin and a proton pump inhibitor in 68 (64%) cases, triple regimens were prescribed in 28 (26%) patients and quadruple regimens in 10 (9.4%). Treatment duration of 7 days was assigned to 2 (1.9%) patients, 10-day eradication therapy in case of 80 (75%) and 14 days - in 24 (23%) patients. Furazolidone was mainly used in first- (79%) and second-line (21%) regimens. The methods used to diagnose H. pylori infection were: histology (81%), stool antigen test (64%), 13C-urea breath test (6.6%), and rapid urease test (1.9%). The mITT effectiveness of sequential therapy was 100%; 93% with the triple therapy and 75.5% with quadruple therapy. Compliance was reported in 98% of cases. Adverse events were revealed in 5.7% of patients, mostly nausea (3.8%). No serious adverse events were reported. CONCLUSION: Furazolidone containing eradication regimens appear to be an effective and safe empirical therapy in Russia.

Enhancing catalytic activity through the construction of praseodymium tungstate decorated on hierarchical three-dimensional porous biocarbon for determination of furazolidone in aquatic samples.

Boosting catalytic performance as a vital role for an electrochemical sensor for monitoring various hazardous nitro drugs. Herein, an inexpensive, facile, and eco-friendly construction of praseodymium tungstate decorated on three dimensional porous biocarbon (PrW/3D-PBC) for electrochemical determination of carcinogenic residue furazolidone (FZ). The nanostructured PrW nanoparticles were prepared by solvent evaporation from peroxo-tungstic acid and 3D-PBC was prepared from biomass precursor under the carbonization method. Furthermore, the composite of PrW decorated on 3D-PBC was prepared by an ultrasonic-assisted wet chemical approach. Besides, the composite characterization of crystalline, functional group, degree of carbonization, chemical states, and morphology were utilized by theXRD, FTIR, RAMAN, XPS, and FESEM analysis. These 3D porous carbon decorated PrW nanoparticles facilitate the electrochemical anchoring sites, surface area, and ease of diffusion layers towards the detection of hazardous nitro pollutant FZ by using CV analysis. The low LOD and high sensitivity were achieved by FZ determination through using LSV and DPV techniques. The practical capability of the PrW/3D-PBC/GCE sensor was determined by using aquatic samples to achieve a good recovery result. These results instigate that the PrW/3D-PBC will be an efficient electrocatalytic material for FZ sensor in environmental aquatic samples.

Multiple Bismuth Quadruple Therapy Containing Tetracyclines Combined with Other Antibiotics and Helicobacter pylori Eradication Therapy.

Helicobacter pylori (HP) infection is closely associated with the development of chronic gastritis, peptic ulcer, and gastric cancer. However, the resistance rate of H. pylori strains to antibiotics such as clarithromycin, metronidazole, and levofloxacin has increased significantly, resulting in a significant decrease in the eradication efficacy of commonly used regimens. Tetracycline has received the attention of domestic and foreign scholars because of its low resistance. The purpose of this review is to provide an update on the tetracycline-containing bismuth quadruple eradication therapy for H. pylori infection and review the efficacy and safety of the regimens, hoping to provide guidance for clinical practice.

A Paper-Based Electrochemical Sensor Based on PtNP/COFTFPB-DHzDS@rGO for Sensitive Detection of Furazolidone.

Herein, a paper-based electrochemical sensor based on PtNP/COFTFPB-DHzDS@rGO was developed for the sensitive detection of furazolidone. A cluster-like covalent organic framework (COFTFPB-DHzDS) was successfully grown on the surface of amino-functional reduced graphene oxide (rGO-NH2) to avoid serious self-aggregation, which was further loaded with platinum nanoparticles (PtNPs) with high catalytic activity as nanozyme to obtain PtNP/COFTFPB-DHzDS@rGO nanocomposites. The morphology of PtNP/COFTFPB-DHzDS@rGO nanocomposites was characterized, and the results showed that the smooth rGO surface became extremely rough after the modification of COFTFPB-DHzDS. Meanwhile, ultra-small PtNPs with sizes of around 1 nm were precisely anchored on COFTFPB-DHzDS to maintain their excellent catalytic activity. The conventional electrodes were used to detect furazolidone and showed a detection limit as low as 5 nM and a linear range from 15 nM to 110 µM. In contrast, the detection limit for the paper-based electrode was 0.23 µM, and the linear range was 0.69-110 µM. The results showed that the paper-based electrode can be used to detect furazolidone. This sensor is a potential candidate for the detection of furazolidone residue in human serum and fish samples.